Float controlled electric switch



March 7, 1939. A B MQJONNIER 2,149,619

FLOAT CONTROLLED ELECTRIC SWITCH Filed Aug. 21, 1937 I 'jj i6 18 I [I 22 f 26* 293420 3 a? 2/ F534 .3 jg g? Imfen'ro r riias j -17! Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE Albert B. Mojonnier, Park Ridge, 111., assignor to Mojomiier Bros. (10., a corporation of Illinois Application August 21,

1 Claim.

The present invention relates to float controlled electric switches and has for its general object the production of a switch of this type such that when associated with the container with which it is to be used, it may be readily positioned and removed, and also separated into units which may be easily and thoroughly cleaned.

The invention is useful in all cases wherein the container and associated float and switch carrying parts have to be periodically cleaned. This is especially true where milk or milk products are being handled. However, as is obvious, the invention is capable of general use with all kinds of liquids.

For a full understanding of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawing, while, for a measure of the scope of the invention, reference should be had to the appended claim.

In said drawing, Fig. 1 is a perspective view of a small container in association with a float controlled electric switch constructed and arranged in accordance with the present invention. Fig. 2 is a side elevation of a portion of the switch box and an associated pointer which serves to show in a general way the position of the float within the container. Fig. 3 is a plan view of the structure of Fig. 1, parts near the pivotal axis being shown in horizontal section. And Fig. 4 is a sectional elevation of the switch box together with a diagram of electric circuits which illustrate one set of electrical connections for the switch. Throughout these views like characters refer to like parts.

Referring to the drawing in detail, NJ designates a container in which a liquid Il may be located. As shown, the level of the liquid H is well below the top of the container 10. Obvi ously, the liquid may be delivered to and taken from the container ID in any desired way. In brief, the novel mechanism includes a float A and a switch assembly B, both of which oscillate about an axis of rotation CC.

The float A is preferably composed of metal and rides upon the surface of the liquid I I, being partially submerged. The structure of the float may be varied. In the present instance it comprises a central cylindrical tube I2 and end caps l3 which are welded or soldered together along lines l4. Thus, a hollow floatable metal body is produced.

In the axis CC, about which the parts are to oscillate, there is a pivot 15, and an arm l6 connects the float and pivot. The pivot and arm,

1937, Serial No. 160,202

like the float, are made of metal. The connections at both ends of the arm 16 are rigid and may be made by welding, soldering or otherwise, as desired. Thus, the float A, arm 16 and pivot 15 constitute a single unit which may be handled and cleaned as such when removed from the container and switch. The arm 13 and pivot l5 constitute a supporting member for the float A.

The pivot i5 is supported, when the parts are assembled, by a metal bearing sleeve 18 which has a reduced threaded end 19 which is passed through an opening in one of the container walls near its upper edge. When assembled a nut is threaded onto the reduced end it. The location of the bearing I8 is above the level of the liquid H. When the bearing i3 and nut is are in final position, the two are preferably secured to the wall by soldering the two together at one or more points 21, 22.

The outer end of the pivot i5 which in assembled position extends beyond the nut 26 is provided with two kerfs or grooves 23. These are positioned on opposite sides of the pivot l5 so as to extend more or less vertically when the float A is in its normal position upon the level of the liquid. The grooves 23 provide a sort of seat for a pointer 24 which is provided on its under side with a slot 25. The width of the slot 25 is equal to the distance between the bottoms of the grooves 23, or approximately so. Thus the end of. the pivot 15 on the outside of the container I0 .is adapted to receive and hold the pointer 24. The fit between the pivot and pointer is loose enough so that the pointer may be readily lifted away from the pivot 15 or placed thereon Whenever necessary. The direction indicated by the pointer 24 is in approximate agreement with the position occupied by the arm 16. In consequence of this relation, the pointer 24 indicates on the outside of the container 10 the position of the float A on the inside.

The pointer 24 is preferably made out of sheet metal and is provided with a broad extension 26 which forms the rear and bottom walls of the switch box. The top, front, and side walls of the same box are provided by a pressed-up sheet metal member 21 which is secured by rivets 28 to the upper portion of the extension 25. The switch mechanism B, which includes the switch box just described, contains one or more mercury switches 29 which are secured by suitable clips 30 to the back wall of the switch box. In practice the conductors which are connected to the mercury switches pass through a suitable outlet 31 of the switch box in the form of a cable 32 ill and the cable ends in a plug P. The electrical connections are all diagrammatically represented in Fig. 4. As there shown, the cable conductors 33, 34, 35, 36 terminate respectively in the plug contacts 37, 38, 39, :39. The plug contacts in turn cooperate with socket contacts 4!, 42, 43, 44, respectively. These in turn may be variously connected. According to the particular signal circuits of the diagram, contact 4i is connected through signal lamp 45 to a supply lead 46 by means of a conductor 47. Contact 42 is directly connected by conductor 48 with the other supply lead d9. Again, contact 43 is connected by conductor 58 through signal lamp 5! to supply lead 46. And contact 44 is connected directly to ground by conductor 52.

Within the mercury switches, a globule oi mercury 53 cooperates with contacts 5% of one switch and a globule of mercury 55 cooperates with contacts 56 of the second switch.

Now it will be apparent that when the pointer 24 is removed from the pivot 15, it will carry the switch B and one end of the cable 32 with it. Thus the pointer and the parts carried by it constitute a single unit which may be lifted free of the container and moved to one side for cleaning if desired. Indeed, the plug P might be removed from its connection with the socket contacts and all carried away for testing, repairs or the like. Thus, there is the pointer unit and the float unit. These units are separable from each other and from the container, all of which will be obvious from what is described herein.

In operation, it will be seen that when the parts are all in position upon the container l and the container is supplied with liquid I l then the float A will ride upon the surface of the liquid, being partially submerged, as shown. As liquid is removed and added, the float A will fall and rise with the level of the liquid N. In consequence of this falling and rising of the float A, there will be a corresponding rocking of the pointer 24 and the associated switch mechanism 13. As the circuits are shown in the diagram of Fig. 4, the float A occupies a rather high position. As long as the liquid level remains as high as this, there will be no lighting of the signal lamps 45 and This may be called the high level.

Now, in case liquid is withdrawn from the container i t to an extent sufficient to cause the float and pointer to drop down far enough to operate the upper mercury switch, then globule 53 will engage contacts 54 and a circuit will be completed for the signal lamp 45. This circuit may be traced from supply lead 45 through conductor 61, including lamp 45, thence through contacts 4i, 3?, conductor 33, mercury switch contacts 54, conductor 34, contacts 38, 42, and conductor 48 to supply lead 49. Thus the closing of the upper mercury switch contact lights lamp 45. serves as an indication that the level of the liquid in the container is lower than before. This may be called the intermediate level.

If still more liquid be withdrawn from the container, the level will go to a still lower point. This may be the lowest permissible level and may be called the low level. As the liquid is withdrawn and the level thus lowered, the pointer 24, following the float A, will be tilted to a position in which it will cause the lower mercury switch to close its circuit. This will be brought about by the mercury globule 55 engaging contacts 56. Thus a circuit will be closed for the second signal lamp 5i. This circuit may be traced from This supply lead 49 through conductor 48, contacts 42, 38, conductor 34, mercury switch contacts 56, conductor 35, contacts 39, 43, and conductor 50, including lamp 5|, to supply lead 46. The lighting of the second lamp 5| will thus show that the low level has been reached, and appropriate steps may be taken to furnish more liquid to the container or treat the matter as circumstances may require. It will be noted that when the plug and socket contacts are closed, the casing of the switch mechanism B will be grounded by way of conductor 36, contacts 40, 44 and conductor 52.

It will be apparent that the switch mechanism B may be quite difierent than that illustrated. It is intended, however, to employ one or more mercury switches, since the tilting of the parts is relied upon to make and break the circuits. Instead of displaying lamp signals, it is obvious that one or more circuits may be used to control other types of apparatus. What is shown is merely typical. Obviously, the connections might also be made in other ways than through the cable illustrated.

The various metal parts may be variously formed and preferably, a stainless metal is employed. The switch box may also be filled with an insulating compound, a small amount being indicated at 5'! in Fig. 4. This is of course poured in after the tubes and connections within the box have been finally positioned and secured.

From what has been said it will be seen that the float unit and the switch unit may be readily separated from each other and from the container. This leaves all free for separate treatment as may be required, scrubbing and cleaning, or otherwise, as desired.

Obviously, many changes may be made in the disclosed details without departing from the spirit and scope of the invention. Accordingly, it is intended by the terms of the appended claim, to cover all such changes.

I claim:

In a device of the class described, a container having a horizontal bottom and vertical walls, a bearing sleeve passing through and secured to one of said walls near its top, said sleeve extending horizontally and only a short distance into said container, and having a bearing opening extending in the direction of its length and hence horizontally and transversely of the wall to which said sleeve is connected, a pivot adapted to fit snugly within said bearing opening and to extend only slightiy beyond the inner and outer ends of said sleeve, a float arm permanently connected to the inner end of said pivot and extending transversely of the axis of said pivot, a float secured to the free end of said float arm and positioned to ride on liquid in said container, the protruding outer end of said pivot being provided with two grooves on opposite sides forming a seat having walls which extend substantially vertically when said float is in its normal position on the liquid in said container, an outer substantialiy vertical plate formed, first, with a pointer extending lengthwise of said container when said float is in said normal position and, second, with a vertically disposed slot on its under side, said slot having a width approximating the space between the said grooves in said pivot so as to be removably slipped down over the end of said pivot into fitting engagement with the walls of said seat, and a mercury type electric switch secured to said plate so as to make and break circuit in response to the oscillations of said plate in response to up and down movements of said float with changes in the liquid level in said container, said plate and switch constituting a single unit which is readily removable from the outer end of said pivot to free the latter for removal from said sleeve bearing; said float, float arm and bearing being also connected together thus to constitute a unit which may be bodily removed from said container for cleaning by withdrawing said pivot from said sleeve opening after said plate unit has been removed therefrom as aforesaid.

ALBERT B. MOJONNIER. 

